Which of the following devices is BEST suited for servers that need to store private keys?

A.
Hardware security module

B.
Hardened network firewall

C.
Solid state disk drive

D.
Hardened host firewall

Explanation:
A hardware security module (HSM) is a physical computing device that safeguards and manages
digital keys for strong authentication and provides cryptoprocessing.
By adding a HSM to the server and storing the private keys on HSM, the security of the keys
would be improved.